Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE lNV~llON
The present invention relates to a device for con-
trolling a railroad track making or repairing machine, which
comprises on the one hand a laser emitter mounted on a skip
standing on the track or the lay-out thereof ahead of the ma-
chine, and adapted to emit a first fan-shaped or sweeping beam
in a horizontal plane and a second fan-shaped or sweeping beam
in a vertical plane, and on the other hand a laser receiving
unit mounted on the machine and comprising a first receiver for
the horizontal beam and a second receiver for the vertical beam,
both receivers being designed for automatic adjustment as a
function of the impact line of one or the other of said laser
beams at positions corresponding to the desired positions of the
working members of the machine.
Relative-base measuring units have already been used
for performing track levelling and lining works, and mounted
notably on tamper-leveller-liners.
A known feature of relative-base measuring units of
this type is that they reduce appreciably track defects in both
horizontal and vertical planes as a function of their geometry
in a proportion ranging from 1:3 to 1:4. Another feature inherent
to these units is their capacity of reducing the geometric defects
of railroad tracks when their wavelengths are less than 20 m.
On the other hand, to correct track defects when the wavelength
is above 20 m. the use of a longer measurement base consisting
either of an optical system or of a laser system becomes neces-
sary.
Existing laser systems comprise emitters generating
fan-shaped or sweeping beams either horizontally for levelling
operations or vertically for shifting operations. Laser emitters
equipped with special optical systems generate horizontal and
vertical beams either on the same axis or shifted parallel there-
to by means of mirrors. However, this arrangement is objectiona-
ble in that one fraction of the laser power out-put is lost in
the optical system at the expense of precision and of a reduction
in the actual working length. Superposed beams can only be used
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for alignment purposes since the curves of the two receivers do
not follow the same path. Besides, if two separate laser emitters
are used, the vertical beam (for shifting or lining) ~ill inevi-
tably intersect at one time the working field o~ the horizontal
beam for the levelling function, thus rendering the complete
system inoperative.
SUMMARY OF THE lNv~NllON
It is the primary object of the present invention
to avoid this drawback by providing a device characterized by
the fact that the laser emitter system consists of a single
laser emitter of which at least one section controlling the beam
orientation is rotatably mounted and therefore adapted to rotate
about the track-parallel laser axis, and that a motor is provid-
ed for rotating said section between two end positions spaced 90
degrees apart from each other, a irst position corresponding
to the beam operation in the horizontal plane, the second posi-
tion corresponding to the beam operation in the vertical plane.
Thus, shifting operations and levelling operations
can both be carried out by using a single laser emitter generat-
ing a fan-shaped or sweeping beam adapted to operate by turns in
the horizontal plane and in the vertical plane for levelling
and shifting, respectively.
According to a first form of embodiment of the inven-
tion the complete laser emitter is mounted to a support permitt-
ing the rotation of the laser emitter about its track-parallel
` axis.
In a second form of embodiment of the invention the
laser emitter is mounted in a fixed position and only the optical
system directing the fan-shaped or sweeping beam is rotated
through 90 degrees by means of a motor.
In many cases, known track repairing machines, espe-
cially tamping, levelling and lining ~ch;nes~ are provided with
relative measurement bases for levelling and shifting operationsO
In this case, the laser receivers of the present invention are
connected to the relative measurement base for shifting or level-
ling works, respectively, notably at the front end of the relevant
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base, the receiver and the relevant base moving together during
the automatic adjustment of the receiver.
Moreover and preferably, the device of this inven-
tion comprises computer means for calculating the versed sine
or rise of curved horizontal and possibly vertical track sec-
tions as a function of the distance covered by the machine. This
computer is adapted to correct the desired positions of the
working members of the machine, respectively the positions of
said relative measurement bases with respect to the correspond-
ing laser receiver. Of course, this computer may be dispensedwith and the rise may be corrected manually.
For example, in the specific case of a tamping,
levelling and lining machine, this laser emitter control device
may be so designed that at each tie firstly the horizontal beam
is utilized for levelling purposes, whereafter the emitter is
rotated through 90 degrees about its track-parallel axis for
lining or shifting purposes, or vice-versa. It is also possible
to provide control means such that the levelling operation is
accomplished every other tie while the shifting operation is
carried out on the intermediate ties. With this procedure, the
efficiency is increased without impairing the precision, due to
the relative bases which reduce any defects possibly rrm-in;ng
between successive ties.
In the following disclosure the invention will be
described more in detail with reference to the accompanying
drawings.
THE DRAWINGS
Fig.1 is a diagrammatical side elevational view
showing the laser emitter with the receiver for levelling works,
the dash-and-dot line corresponding to the horizontal beam and
the dash line to the vertical beam.
Fig.2 similar to Fig.1 is a plan view from above
showing the receiver for shifting or lining operations, the
vertical beam being shown in dash-and-dot lines and the hori-
zontal beam in dash lines.
Fig.3 is a diagrammatic view showing the laser
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receiver either for shifting or for levelling, with the laser
beam adjusted in position.
Fig.4 is a diagrammatic cross-sectional view show-
ing the track with the levelling and shifting laser receivers.
Fig.5 is a diagrammatic perspective view showing
the basic principle of the device with the two beams and the
two receivers.
Fig.6 illustrates diagrammatically the same device
disposed on a curved track section.
Fig.7 is a diagrammatic cross sectional view show-
ing the track, the overlying receiver for a shifting operation,
and the means for calculating the versed sine or rise of the
curve.
Fig.8 is a simplified side elevational view of the
laser emitter.
Fig.9 is another simplified end view of the laser
emitter with the drive motor.
Fig.10 illustrates diagrammatically a typical form
of embodiment wherein the laser emitter and the shifting
receiver are disposed on the directing line.
Fig.11 is a diagrammatic perspective view showing
the laser emitter and the levelling receiver disposed on the
directing line.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated diagrammatically in Figs.1-9 of the
drawings the principle on which the present invention is based
consists in providing a single laser emitter 1 disposed ahead
of a railroad track making or repairing machine travelling in
the direction of the arrow (Fig.1) and shown diagrammatically
in the form of a chassis 2. This emitter 1 is capable of emit-
ting a fan-shaped or sweeping beam directed either horizontally
for levelling operations (beam Fn) or, after a 90 degree rota-
tion, vertically, for shifting or lining operations (beam Fr),
a levelling receiver Rn and a shifting receiver Rr being both
mounted on the same machine.
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In Fig.1 showing a side eleva-tional view of the
device controlling the levelling operation, the irregular line
3 illustrates the old track to be corrected; however, to faci-
litate the understanding of this Figure the defects of the
railroad tracks have been exaggerated considerably. The dash
lines on the right side of the Figure illustrate the freshly
corrected track section, line 4 showing the new track as cor-
rected; finally, chain line 4' illustrates the desired track
defined by the laser axis which, during the initial phase of
the operation, is set parallel to this desired track.
The device comprises a laser emitter 1 adapted to
emit a horizontal beam Fn. This emitter is mounted on a skip 5
disposed at a fixed location suitably selected along the old
track 3, ahead of the machine which, in this specific example,
is a tamping, levelling and shifting machine shown diagrammati-
cally as comprising the chassis structure 2 and simply designat-
ed in the following disclosure by the term "machine". This ma-
chine is provided with a known relative measurement base, for
example a probe, at each one of the track points A,B,C. Point C
lies on the already corrected track section 4, point A lies on
the old track 3, and point B is the working point lying there-
fore in the vicinity of the working members intended for posi-
tioning the track and consisting in the known fashion of shift-
ing and levelling clamps. In the example illustrated in Fig.1
the position of point A is somewhat exaggerated and point B has
just been corrected, like point C, and the machine with its
chassis 2 is inclined forwards and downwards.
At point A is a laser receiver Rn for levelling ope-
rations which is adapted to be set vertically in relation to
the chassis 2 by means of an adjustment motor Mn. Secured to
this receiver Rn is a member supporting the front end AL of
the reference line Ln of the relative measurement base for le-
velling operations. This end AL overlies point A. In this case,
the reference line Ln is assumed to consist of a taught wire
stretched above the machine, with one end fastened at point CL
disposed vertically above point C and at point BL above point B
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for controlling in a manner known per se, through its position
and by means of suitable drive means, the position of the level-
ling clamps.
The levelling laser receiver Rn, like the shifting
laser receiver Rr to be discussed presently, comprises four
photoelectric cells C1,C2,C3 and C4 ~Fig.3) and is so designed
that it can be moved to the desired position by means of an
adjustment motor Mn as a function of the line of impact of the
horizontal laser beam Fn with respect to said cells, the
adjustment taking place when the beam lies exactly between the
two central cells C2 and C3.
In the example shown in Fig.1, this adjustment has
already been made in such a way that the reference line Ln
which, before the correction, was in the position designated by
line L'n, is now in the proper position, that is, parallel to
the laser axis Ln. In other words, point BL was corrected verti-
cally by the difference x corresponding exactly to the vertical
correction x to the working point B representing the vertical
distance through which the track was raised by means of the
clamps to the desired position. Under these conditions, BC is
corrected track section and AB the uncorrected track section.
Of course, this reference line Ln may consist of
an~ other mechanical or non-mechanical means, for example a
light ray, and the aforesaid points A and C are not compulsorily
located on the chassis 2 since they may be disposed on small
auxiliary skips rolling at a fixed distance ahead or behind the
chassis 2.
In actual practice, when operating on a track sec-
tion comprising not too many curves, the skip 5 supporting the
laser emitter 1 may be disposed initially at a distance of about
300 m from the machine and when, during the track repairing
works, the machine is too close to the emitter the skip 5 is
moved again to a position spaced about 300 m from the machine.
Of course, when operating on hilly or undulated grounds, care
must be taken that no obstacle exists between the emitter and
the receiver.
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Fig.2 illustrates in a manner similar to Fig.1 a
top view of the shifting control device operating in conjunction
with a vertical laser beam Fr. The chassis-mounted shifting
receiver Rr is adjustable in relation to the chassis proper by
means of transverse guide member as a function of the vertical
beam Fr under the control of a motor Mr. A reference line Lr
is connected to this receiver Rr and the reference line L'r in
its uncorrected state is shown in dash line by way of example.
It will thus be seen that in this example, at point B corres-
ponding to theshifting clamps, the difference due to the pre-
viously made correction is denotecl by the distance y. In Fig.2
it will also be seen that the position A of the reference point
comprises the two points AG on the left-hand rail and AD on the
right-hand rail.
Fig.4 illustrates diagrammatically a cross-sectional
view of the track at the location of the levelling and shifting
receivers Rn and Rr, respectively, which shows their relative
positions and in this specific case it is assumed that the
shifting receiver Rr is coincident with the track axis, the
levelling receiver Rn being positioned on the directing line
which as a rule is the lowermost rail in a curve.
In order to simplify the drawing in Figs.1 to 4,
the device for correcting the reference line as a function of
the horizontal or vertical versed sine, height or rise of the
arc in relation to the receiver has been omitted from these
Figures. Therefore, in fact the coupling between the receivers
and the reference line is not a perfectly rigid one, since it
re~;ns fixed and constant during the adjustment as a function
of the laser, and yet can be corrected as a function of the
measurement of the versed sine or rise! as will be explained
presently with reference to Fig.6.
Fig.5 illustrates simultaneously the two systems in
perspective and it will be seen that the horizontal beam Fn and
vertical beam Fr, together with the two receivers, namely the
levelling receiver Rn adapted to travel vertically and the
shifting receiver Rr adapted to move horizontally. The laser
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emitter 1 is positioned on the track axis.
Fig.6 shows the mode of operation of the shifting
system in a curved track section having a radius r. Initially,
the laser bea~ Fr generates a chord between the emitter 1
disposed ahead of the machine and the shifting receiver Rr
- supported by the machine. In the initial position, the receiver
Rr and the reference line are at point Ao on the median line
of the track. During the operation, if the machine is moved in
the direction of the arrow S, it ~ollows the track curvature
while the shifting receiver follows the vertical beam Fr of
the laser along the chord having a length G, the movement of
this receiver depending on the versed sine of the arc external-
ly of the median line. Thus, for example, if this receiver is
at point A1, it has covered the distance corresponding to the
versed sine or rise f1. Of course, in this case the relative
measurement base, respectively the reference line, must not
follow the receiver since this line determines the position of
the working clamps at point B; therefore, the rise f1 is calcu-
lated as a function of the curve, and the reference line is
shifted by a distance f1 in relation to the receiver externally
of the curve. Similarly, when the laser receiver Rr is at point
A2, the reference line is moved to the extent corresponding to
the versed sine or rise of arc f2, which is the distance
between the position of receiver Rr adjusted on the beam and
the reference line determ;n;ng the position of the working
members on the desired curve.
Fig.7 further illustrates in diagrammatic cross
section the track at the above-defined point A2. The receiver
Rr has covered a distance f2 externally of the ~ledian line, but
on the other hand the front end of reference line Lr (extending
at right angles to the plane of the Figure) must also be moved
through this distance f2 to the desire position,i.e. the centre
of the track. Consequently, the front end of reference line Lr
is also movable in a transverse direction with respect to
receiver Rr. Whereas in Fig.2 showing a straight track section
the end of reference line Lr is disposed centrally of receiver
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Rr, in the example of Fig.7 the end of this line Lr is shifted
by the distance or rise f2 by means of a motor Mf supported by
the chassis 2. To calculate the rises or versed sines fl ,f2. . .
fn as the machine is travelling in the foxward direction, a ri-
se computer UC and an apparatus UM for calculating the distance
covered by the machine are used. The computer UC calculates
the rise f in a known fashion as a function of the radius r of
the curve and the length G of the chord, and actuates a position-
ing motor Mf adapted to move the support of reference line Lr
according to the calculated value in order to correct the rise
C~, while the position of receiver Rr is controlled by the ver-
tical beam Fr by means of a motor Mr to correct the shifting Cr.
A typical laser emitter suitable for operating with
the above-described device is illustrated in Figs.~ and 9 of
the drawings. This laser emitter 1 is of conventional type and
comprises at the front an optical system 10 for generating a
fan-shaped or sweeping beam, consisting of at least one lens
element or an oscillating deflection mirror. The laser emitter
1 with its fan-shaped or sweeping system is mounted in ball-
bearings 11 for rotation about its central axis ~ parallel tothe track. The assembly is carried by a support 12 adapted to
be adjusted both vertically and horizontally by means of
adjustment screws 13 and 14, respectively. The laser emitter is
further connected through an arm 15 (Fig.3) to one end of a
rod 16 adapted to be actuated by a motor 17, preferably an
electric motor, for rotatin~ the emitter 1 through an angle of
90 degrees about its axis 2 according as the beam is to be
vertical or horizontal.
According to a preferred form of embodiment, this
motor 17 is associated with a radio receiver 18 for controlling
the motor from the machine.
In another form of embodiment of the invention the
laser emitter proper is mounted in a fixed position and only
the optical device generating the fan-shaped or sweeping beam
is rotatably mounted so that it can swivel about the laser axis
under the control of a suitable motor.
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Fig.10 is a diagrammatic perspective view illustrating
a modified method of utilizing the device of the invention. In
this case, the laser emitter 1 generating the vertical beam Fr
is disposed on the directing line and the shifting receiver Rr
is disposed likewise on the directing line. In this specific
e~ample the correction of shifting Cr and the correction of rise
Cf are also shown diagrammaticallyr
A modified mode of operation of the device is also
shown in Fig.11, wherein the laser emitter 1 generating the
horizontal beam Fn and the laser le.velling receiver Rn are both
disposed on the directing line. The levelling correction Cn
shown also diagrammatically may if desired be completed with a
vertical rise correction, in the case of a track section having
a vertical curvature.
The above-described control device may be used in ac-
tual practice in any of the two following ways:
- The track is levelled and shifted at each tie; in
other words, at each tie for example firstly the track is level-
led by operating with the horizontal laser beam, and then the
shifting operation is carried out after rotating the laser
emitter through 90 degrees for operating with the vertical beam;
- The track is levelled only every other tie, and shifted
at each intermediate tie.
Of course, the invention should not be construed as
being strictly limited by the specific form of embodiment
described and illustrated herein, since it is also possible to
operate without any relative measurement base. In this case, the
working members or clamps are controlled directly by the level-
ling receiver or the shifting receiver, respectively.
Moreover, this device comprising only one laser emitter
is applicable to any other railroad txack repairing machine, for
example a ballast-clearing machine, a track relaying train or a
train for laying new tracks.
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